Integrated models of offshore wind turbines

Transcription

1 NOWITECH final event August 2017 Integrated models of offshore wind turbines Tor Anders Nygaard, Senior Scientist Institute for Energy Technology (IFE)

2 Outline Integrated models; what is it? Where did we start eight years ago? OC3-Hywind, IEA Code to Code Comp. Where are we now? OC5 Validation against experimental data NOWITECH validation examples Is it going to pay off? Unexpected, positive side effects What next?

3 Integrated models Stability and fatigue at rated power Survival at ultimate limit state 3

4 Status at NOWITECH start Prior work at Hydro/Statoil: Pitch controller stability, inclusion of hydrodynamics in DTU FLEX5 Simulations with DTU HAWC2 Model test of HYWIND Spar-buoy at MARINTEK Offshore Code Comparison Collaboration within IEA Wind Task 23 (OC3) Code to code comparison of simulation of different wind turbines MARINTEK, IFE/NMBU and NTNU participated from

5 Code to code verification: IEA OC3/OC4/OC

6 Offshore Code Comparison Collaboration within IEA Wind Task 23: Phase IV Results Regarding Floating Wind Turbine Modeling Jonkman, J.; Larsen, Torben J.; Hansen, Anders Melchior; Nygaard, T.; Maus, K.; Karimirad, M.; Gao, Z.; Moan, T.; Fylling, I.; Nichols, J.; Kohlmeier, M.; Pascual Vergara, J.; Merino, D.; Shi, W. Published in: EWEC 2010 Proceedings online FAST Bladed ADAMS HAWC2 3Dfloat Simo SESAM / DeepC Code Developer NREL GH MSC + NREL + LUH Risø-DTU IFE-UMB MARINTEK DNV OC3 Participant NREL + POSTECH GH NREL + LUH Risø-DTU IFE-UMB MARINTEK Acciona + NTNU Aerodynamics ( BEM or GDW ) + DS ( BEM or GDW ) + DS ( BEM or GDW ) + DS ( BEM or GDW ) + DS ( BEM or GDW ) BEM None Hydrodynamics Airy + + ME, Airy + PF + ME ( Airy + or Stream ) + ME Airy + + ME, Airy + PF + ME Airy + ME Airy + ME Airy + PF + ME Airy + + ME, Airy + PF + ME Control System (Servo) DLL, UD, SM DLL DLL, UD DLL, UD, SM UD DLL None Turbine: FEM P + ( Modal / MBS ), Moorings: QSCE Turbine: FEM P + ( Modal / MBS ), Moorings: UDFD Turbine: MBS, Moorings: QSCE, UDFD Structural Dynamics (Elastic) Turbine: MBS / FEM, Moorings: UDFD Turbine: FEM, Moorings: FEM, UDFD Turbine: MBS, Moorings: QSCE, MBS Turbine: MBS, Moorings: QSCE, FEM Airy + Airy wave theory GDW generalized dynamic wake PF linear potential flow with radiation & +) with free surface corrections FEM P finite-element method diffraction BEM blade-element / momentum P) for mode preprocessing only QSCE quasi-static catenary equations DLL external dynamic link library MBS multibody-dynamics formulation SM interface to Simulink with MATLAB DNV Det Norsk Veritas ME Morison s equation UD implementation through user-defined DS dynamic stall MSC MSC Software Corporation subroutine available UDFD implementation through user-defined forcedisplacement relationships 6

7 Data used for validation, NOWITECH,1 HYWIND demo, full scale prototype measurements (partly available? ) Wave tank tests of fixed, rigid and flexible cylinders at MARINTEK and DTU (IEA OC5) Wave tank tests of semisubmersible at MARIN (IEA OC5) Full-scale data, bottom-fixed wind turbines from Alpha-Ventus (IEA OC5, ongoing) Wave tank test of Tension-Leg-Buoy at IFREMER, Brest (IFE/NMBU) MARINET Wave tank test (software-in-the loop) of OO Star Semi at ECN, Nantes (CENER/IFE/NMBU) MARINET Wave tank test of catenary mooring line with forced motion of fairlead, ECN, Nantes (CENER/IFE/NMBU) (Wave tank test of semi-submersible wind/wave energy converter (NTNU) MARINET?) Wave tank test (software-in-the loop) of semi-submersible at MARINTEK Wave-tank test of monopile at MARINTEK (ongoing) 7

8 Data used for validation, NOWITECH,2 Wind tunnel tests of wind turbine rotors at NTNU MEXICO and MEXNEXT wind tunnel tests, IEA projects 8

9 Fixed, flexible cylinders DHI and DTU. IEA OC5 Robertson, A., Wendt, F., Jonkman, J., Popko, W., Borg, M., Bredmose, H., Schlutter, F., Qvist, J., Bergua, R., Harries,R., Yde, A., Nygaard, T.A., De Vaal, J.B., Oggiano, L., Bozonnet, P., Bouy, L., Sanches, C.B, Garcia, R.G, Bachynski, E., Tu, Y., Bayati, I., Borisade, F., Shin, H., van der Zee, T., Guerinel, M. (2016). OC5 Project Phase Ib: Validation of Hydrodynamic Loading on a Fixed, Flexible Cylinder for Offshore Wind Applications. Energy Procedia 2016 ;Volume 94. pg

10 1 0 Fixed, flexible cylinders, some results

11 1 1 OO Star Semi, ECN, Nantes Azcona, J., Bouchotrouch, F., González, M., Garciand, J., Munduate, X., Kelberlau, F. and Nygaard, T.A. (2014). Aerodynamic Thrust Modelling in Wave Tank Tests of Offshore Floating Wind Turbines Using a Ducted Fan. Journal of Physics: Conference Series 524 (2014) Azcona, J., Munduate, X., González, L., and Nygaard, T.A. (2017). Experimental Validation of a Dynamic Mooring Lines Code with Tension and Motion Measurements of a Submerged Chain. Ocean Engineering 2017, Vol. 129, pg

12 1 2 OO Star Semi, some results From Azcona et al., 2014 From Masters s thesis of Engelsvold, NMBU, 2015

13 1 3 Semisubmersible, MARINTEK [1] Thomas Sauder, Valentin Chabaud, Maxime Thys, Erin E. Bachynski, Lars Ove Sæther (2016). Real time hybrid model testing of a braceless semisubmersible wind turbine: Part I: The hybrid approach. In 35th International Conference on Ocean, Offshore and Arctic Engineering, no. OMAE [2] Erin E. Bachynski, Valentin Chabaud, Thomas Sauder (2015) "Real time hybrid model testing of floating wind turbines: sensitivity to limited actuation". Energy Procedia. vol. 80.

14 1 4 Semisubmersible, MARINTEK, some results Luan, C. et al. (2017). Experimental validation of a time-domain approach for determining sectional loads in a floating wind turbine hull subjected to moderate waves. Deepwind 2017.

15 Semisubmersible, MARIN. IEA OC5 Participant 4Subsea CENER CENTEC Code OrcaFlex- FAST v8 FAST v6 + OPASS FAST v8 Aerodyn. Hydrodynamics Moorings Dyn. Wake Unst. Airfoil 2 nd + WK 1 st PF 2 nd PF ME Meas. Wave Stretch Inst. Pos. Dyn. Hydro Exc. Seabed Fric. DNV GL Bladed 4.8 DTU ME DTU PF ECN-MARIN IFE IFP_PRI NREL PF HAWC2 HAWC2 a NySIM- PHATAS v10 3DFloat DeepLines Wind V5R2 FAST v8 Diff.- only NREL ME FAST v8 POLIMI FAST v8.15 Siemens PLM Tecnalia F7O Sa mcef Wind Turbi nes FAST v7 + OrcaFlex 9.7 Tecnalia F8 FAST v8.16 Diff.- only UC-IHC UOU UPC UTokyo WavEC FAST WavEC FF2W Sesam UOU + FAST v8 UPC + FAST NK-UTWind FAST v8 FF2W Robertson, A. et al. (2017) OC5 Project Phase II: Validation of Global Loads of the DeepCwind Floating Semisubmersible Wind Turbine. Deepwind

16 Semisubmersible, MARIN, IEA OC LC33 CENER 6 CENTEC DNV-GL2 DTU-ME DTU-PF 5 ECN-MARIN IFE 4 NREL NREL-ME 2 /Hz) IFPEN-PRI POLIMI TwrBsFxt (kn 3 SIEMENS-PLM TECN-F7O TECN-F8 UC-IHC 2 UOU UPC UTOKYO 1 WAVEC-FAST WAVEC-FF2W 4SUBSEA EXPERIMENT Frequency (Hz) Fig. 9. PSD of the tower-base shear force for operational wave excitation, using a significant wave height of 7.1 m and peak period of 12.1 s 1 6

17 1 7 Evolution during NOWITECH Higher-order wave kinematics More detailed load models Experience with what approaches can be used for different types of floaters Advanced rotor aero-elasticity Soil/structure interaction From verification (code to code) to validation (experimental data) Education and training of analysts. The complexity of offshore wind turbines makes the person doing the analysis as important as which model is being used.

18 1 8 Will it pay off?

19 1 9

20 2 0 Unexpected, positive side effects New conceptual designs for long, floating bridges for E39 required time-domain simulations with full coupling between a flexible structure, turbulent wind and irregular waves. The ability of 3DFloat and SIMO/Riflex to offer this capability is a direct result of floating wind turbine work in NOWITECH. More accurate time-domain simulations can potentially reduce overly concervative designs, and thereby costs. 1% of cost reduction for a bridge with cost 20e9 NOK (20 billion, milliarder) is 200 MNOK. The work package for integrated models in NOWITECH had a total cost of?? MNOK of the total research budget of 320 MNOK.

21 2 1 Conclusions and the way forward The integrated models have improved considerably over the last ten years Education and experience gained for engineers is important as well We still have a lot to do; give 10 groups identical models and identical geomtery definitions, and you will still see some spread of the results! Computational Fluid Dynamics (CFD), not treated in this presentation will play an increasing role, both for hydrodynamics and aerodynamics, in full coupling with structural dynamics.